class User {
   name = "hello"
   age = 22
  constructor(sex = '保密') {
    this.sex = sex
    this.show = function(){
      console.log('i am show 方法')
    }
  }
  info() {
    return `姓名: ${this.name}, 年龄: ${this.age}, 性别: ${this.sex}`
  }
}

var a = new User('男');
console.log(a)
console.log(a.info())








